Loading and release of insulin from chitosan oligosaccharide biopolymeric patch for oromucosal delivery

Delivering protein/peptide-based drugs through oral administration is challenging. Currently, these drugs are delivered via the parenteral route. However, the gastrointestinal mucosal epithelium presents a non-invasive and feasible alternative, but oral formulations for these drugs require protease inhibitors and permeation enhancers. The oral mucosal epithelium, specifically the buccal and sublingual mucosa, is an attractive route for both local and systemic drug delivery. In this report, we present a chitosan oligosaccharide (COS)-based patch for oromucosal drug delivery that encapsulates insulin as a model peptide drug. Our analysis of insulin loading and in vitro release from the polymer matrix revealed that 50–60% of the insulin was released after 2 h. To the best of our knowledge, this is the first report of the fabrication of a COS-based mucoadhesive patch as a prototype for successful oromucosal delivery of insulin.